rich p roject o verwie v

RICH PROJECT OVERWIEV

Contalbrigo Marco INFN Ferrara

Rich Project Review, 5th September 2013

DC R3R2R1EC

Torus

FTOF

PCAL

HTCC

Solenoid

RICH

The CLAS12 Spectrometer

2 Rich Technical Review, 5th September 2013, JLabContalbrigo M.

RICH: Hadron ID for flavor separation(common to SIDIS approved exp.)

Luminosity up to 1035 cm-2 s-1

Broad kinematic range coverage (current to target fragmentation)

H and D polarized targets

Highly polarized electron beam

PAC30 report (2006): Measuring the kaon asymmetries is likely to be as important as pions …. The present capabilities of the present CLAS12 design are weak in this respect and should be strengthened.

Beam

E12-09-07: Studies of partonic distributions usingsemi-inclusive production of Kaons

E12-09-08: Studies of Boer-Mulders Asymmetry in Kaon Electroproduction with Hydrogen and Deuterium Targets

E12-09-09: Studies of Spin-Orbit Correlations in Kaon Electroproduction in DIS with polarized hydrogen and deuterium targets

CLAS12

CLAS12

RICH detector for flavor separation of quark spin-orbit correlations in nucleon structure and quark fragmentation

Kaon SIDIS Program @ CLAS12

3Contalbrigo M. Rich Technical Review, 5th September 2013, JLab

4Contalbrigo M.

SIDIS Kinematics @ CLAS12

Out-bending particles In-bending particles

Rich Technical Review, 5th September 2013, JLab

A rejection factor of 1:500 is needed to suppress the background from a one-order of magnitude larger pion-proton flux to a few % level

5Contalbrigo M.

SIDIS Kinematics @ CLAS12


Pion mis-ID Kaon mis-ID

kaon pion

A pion rejection factor of 1:500 for a 90% kaon efficiency corresponds to a 4s separation in the time (TOF) or angular (Cherenkov) distributions

n-sigma separation

540 1 2 3

1

10-1

10-2

10-3

10-4

p m

is-ID

90% kaon efficiency

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Baseline PID @ CLAS12

HTCC (electron ID):High Threshold Cherenkov Counter

FTOF (< 3 GeV/c hadron ID):Forward Time-of-Flight system

LTCC (pion ID):Low Threshold Cherenkov Counter

HTCC

LTCC FTOF


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FTOF @ CLAS12Two scintillators panels for hadron ID: 5 cm thick, 32-375 cm long slabs

Panel 1a: from CLAS, 15 cm widePanel 1b: new, 6 cm wide

Combined expected resolution: 45-80 ps

4s = 0.18 nsSuitable hadron separation achievedby time-of-flight at 650 cm from IP:

Up to 2.8 GeV/c (q = 36 degrees)Up to 3.6 GeV/c (q = 5 degrees)


4s = 0.32 ns

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HTCC @ CLAS12New detector for electrons ID:

CO2 radiator48 5” quartz window PMTs Hermetic with uniform response

Expected p.e. number with electrons ~ 16

Pions in-efficiency for minimum 2 p.e. number:

100% below 5 GeV/c (Cherenkov threshold)

~ % level around 6 GeV/c

~ few per mil above 7 GeV/c


4s cut1 Npe2 Npe

3 Npe

p

Pion in-efficiency for minimum Npe

Npe

Electrons

Pions

Requested pion separation achieved above 7 GeV/cNo kaon-proton separation

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LTCC @ CLAS12Derived from CLAS for pion ID:

C4F10 radiatorComplicated design with irregular response Limited f acceptance

Expected p.e. number with electrons ~ 9

Pions in-efficiency for minimum 2 p.e. number:

100 % below 2.7 GeV/c (Cherenkov threshold)

~ % level around 5 GeV/c

~ per mil level above 7 GeV/c


Npe

Electrons

Pions

4s cut

1 Npe 2 Npe3 Npe

Pion in-efficiency for minimum Npe

Requested pion separation achieved above 8 GeV/cNo kaon-proton separation

Aerogel mandatory to separate hadrons in the 3-8 GeV/c momentum range with the required large rejection factors

collection of visible Cherenkov light use of PMTs

Challenging project, need to minimize detector area covered with expensive photodetectors

CLAS12 Momentum Range

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SIDIS kinematicsTOF


Ratio K/p ~ 0.1-0.15

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SIDIS Kinematics @ CLAS12Intermediate angular range (15-25o) important to reach high PT values

High Momentum region important astransient to hard semi-exclusive region


PT distribution

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RICH Requirementsz distribution

Full momentum coverage from 3 up to 8 GeV/c Pion rejection above 3 GeV/c Proton rejection above 5 GeV/c

Angular coverage reaching above 20 and up to 25 degrees

Contamination limited at the few % level Pion rejection close to 500 Proton rejection close to 100

1

10-1

10-2

10-3

10-4

p mis-ID

90% kaon efficiency

n-sigma separation 0 1 2 3 4 5


RICH

RICHRICH

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INSTITUTIONS

INFN (Italy) Bari, Ferrara, Genova, L.Frascati, Roma/ISS

Jefferson Lab (Newport News, USA)

Argonne National Lab (Argonne, USA)

Duquesne University (Pittsburgh, USA)

Glasgow University (Glasgow, UK)

J. Gutenberg Universitat Mainz (Mainz, Germany)

Kyungpook National University, (Daegu, Korea)

University of Connecticut (Storrs, USA)

UTFSM (Valparaiso, Chile)

The CLAS12 RICH

RICH goal: p/K/p identification from 3 up to 8 GeV/c and 25 degrees ~4s pion-kaon separation for a pion rejection factor ~ 1:500


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RICH Base Configuration

1st sector by the end of FY16: one year beforeunpolarized and longitudinal polarized target physics runs

2nd++ sector important for transverse target physics runs (left-right symmetry and statistics)


CLAS12 Geometry Constraints

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25o

FTOF w

all

DC

3TORUS

538 cm

124 cm

Base Numbers

5 m from IP

~ 1 m gap

Several m2 surface

Charged particle

Proximity gap

Radiator Photon detector

Proximity RICH


RADIATOR

Aerogel Radiator


Aerogel Transmission Length

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0

10

20

30

40

50

60

70

1.00 1.05 1.10 1.15 1.20 1.25 1.30

refractive index @405nm

transmission length

@400nm [mm]

conventionalPD

pinhole drying process

crack free

“initial alcogel”

“Pinhole drying (PD)” method:artificially shrinks alcogel to obtain high index Transparency doubled for n>1.05 aerogel

M. Tabata @ RICH 2010

A.F. Danilyuk @ RICH 2010

Dens., g/cm3 n Lsc(400), mm0.325 1.070 41.90.302 1.060 56.5


Aerogel Tests(L. Pappalardo)

BELLE II test-bench 15 p.e. with aerogel of n ~ 1.05 refractive index and 4 cm thickness

HERMES experiment 10 p.e. with aerogel ofn ~ 1.03 refraction indexand 5 cm thickness butlower transmittance

LHC-B7 p.e. with aerogel ofn ~ 1.03 refraction indexand 5 cm thickness but64% packing factor5 8 5 8 5 8 5 8 5 8 5 8

P (GeV/c)

Mean p.e. Number (5-8 GeV/c)


New geo

BELLE II test-bench 15 p.e. with aerogel of n ~ 1.05 refractive index and 4 cm thickness

HERMES experiment 10 p.e. with aerogel ofn ~ 1.03 refraction indexand 5 cm thickness butlower transmittance

LHC-B7 p.e. with aerogel ofn ~ 1.03 refraction indexand 5 cm thickness but64% packing factor5 8 5 8 5 8 5 8 5 8 5 8

P (GeV/c)

Mean p.e. Number (5-8 GeV/c)

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CLAS12 Prototypen=1.05, 2 cm


New geo

HERMES experiment 7.6 mrad single photonresolution, dominated by the ~ 2 cm pixel size

LHC-B3 mrad single photonresolution with ~ 3 mm comparable pixel size

5 8 5 8 5 8 5 8 5 8 5 8

P (GeV/c)

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Mean p/K Separation (5-8 GeV/c)


New geo

HERMES experiment 7.6 mrad single photonresolution, dominated by the ~ 2 cm pixel size

LHC-B3 mrad single photonresolution with ~ 3 mm comparable pixel size

5 8 5 8 5 8 5 8 5 8 5 8

P (GeV/c)

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CLAS12 Prototypen=1.05, 2 cm

6 mm pixel size

Mean p/K Separation (5-8 GeV/c)


RICH Prototype(M. Mirazita)

New geo

PHOTODETECTOR

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Photon Detectors: MA-PMT


✓ Mature and reliable technology✓ Large Area (5x5 cm2) ✓ High packing density (89 %) ✓ 64 6x6 mm2 pixels cost effective device ✓ High sensitivity on visible towards UV light✓ Fast response

The only option to keep the schedule is the use of multi-anode photomultipliers (we consider the promising SiPM technology as the alternative)

H8500 Tests(M. Hoek)

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Magnetic Field

B (Gauss)

x (cm)

Y (c

m)

The torus fringe-field allows the use ofMulti-Anode Photomultipliers


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109 n/cm-2/yearat 1035 cm-2s-1

Radiation Damage: NeutronsGammas: Neutrons:

Neutrons:


Measured fluence @ Belle:90/fb 1-10 109 n/cm2

Expected fluence @ Belle-2:50/ab 2-20 1011 n/cm2

Expected fluence @ LHCB-2:1 year 6 1011 n/cm2

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MA-PMTs Readout


Front-End Electronics(E. Cisbani)

DAQ and Trigger(C. Cuevas)

VME DAQ Optics FPGA moduleDeveloped for GLUEX and JLAB12

MAROC3 Front-End card with digital and analog readout tested with the prototype

DREAM Front-End card developedfor JLAB12 micromegas readout

Basic components withalready existing designsand prototypes

THE MIRROR SYSTEM

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Goals: • instrument only forward region • reduce active area (~1 m2/sector)• minimize interference with TOF system

Low material budget

Direct & reflected photons

The Mirror System

Mirrors to focus the Cherenkov light of particles emitted at angles J > 13 deg.

HTCC


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• Direct rings for high momentum particle best performance !

The Mirror System

• Minimize photon detector area cost !

• Open detector close to beam line background !

• Reflected rings for low momentum particle less demanding• Minimum interference with TOF

• Multiple passages within aerogel photon losses • Focalising mirrors allow for thicker aerogel (to partly compensate the loss of photons)

plane mirror

spherical mirror

photon detector

aerogel

1 cm

3 cm

gapAerogel

Spherical mirrors

Photo-detectors

Planarmirrors

Proximity Focusing RICH + Mirrors


26

Integration in CLAS12(M. Contalbrigo)

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Mirror TechnologyThin glass skin on a flat support

for planar mirrorsMetalized Carbon Fiber substrate

for spherical mirror

Cost-effective technology for preciselarge area mirrors

(applications in terrestrial telescopes)

Self-supporting structure with minimal material budget

(applications in physics experiments)

MAGIC-II telescopeLHCB mirror


Mechanical Design(S. Tomassini) standard technologies already in use and commercially available

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RICH Project Achievements

2010: ✔ Concept of Design and Technology

2011: ✔ Tests of components and small prototype

2012: ✔ July: Test-beam with Electrons (Frascati)

✔ July: Test-beam with Hadrons (CERN)

✔ December: Test-beam with Hadrons (CERN)

2013: ✔ February: Start Engineering Phase ✔ 26-27 June: Technical Review


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Technical Review Outcome


Very fruitful discussion and positive response:

“A talented and dedicated collaboration is aggressively pursuing the development of a detectorthat would significantly enhance the capabilities of the CLAS-12 baseline design. Retrofitting adetector into predetermined constraints is always a challenge. Much progress has already beenmade. Although several challenges remain, the panel offers their strong encouragement tocontinue. The potential gain is high.”

14 valuable recommendations: We implement actions for all. Many are addressed already in the TDR and in the presentations. More details are provided in the backup slides of this talk.

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RICH outlook

Summer 2013:

✔ August: Finalize CLAS12 RICH Project (TDR)

✔ August: Finalize Project Management Plan ✔ 5-6 September: Project Review with DOE

✔ September: Ready for Construction

GOAL: 1st sector ready by the end of FY16


Management Plan(P. Rossi)

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Technical Review Recommendations1) We recommend that a full Monte Carlo of CLAS with a RICH sector be developed.A report should be generated for review by CLAS management to document the simulation and the expected performance of CLAS with a RICH, both the enhanced performance in Kaon separation as well as the extent of any degradation in the response of other CLAScomponents. A full RICH simulations was implemented in the CLAS12 GEMC simulation platform under construction: the result are reported in chapter 13 of TDR and in the “Integration in CLAS12” talk.

2) We recommend that at least average properties such as index of refraction, transmission andclarity be measured and recorded for each tile prior to installation. We recognize the addedpotential challenge to the tight time constraints and urge the collaboration to develop proceduresrequired to expedite such a chain of measurements. See answer to recommendation n.3. 3) We recommend that, given the large tile size, the variation of the index of refraction across atile be measured for a sample of tiles, and the typical variation be included in the RICH MonteCarlo.

Improved and extended procedures are being defined as described in chapter 3 of TDR and in the “Aerogel Tests” talk: a semi-automatized characterization of each tile is foreseen.


36Contalbrigo M.

Technical Review Recommendations

4) We recommend that the collaboration obtain samples of Novosibirsk tiles fabricated withsmooth planar surfaces and assess their optical properties. A new dedicated production will start beginning of September 2013. 5) We recommend that the collaboration investigate the potential background from scintillations in the gas within the RICH chamber and the affect on the Aerogel of any mitigating measures.

We estimate a manageable maximum 4 p.e. background for a 1m pure-N2 gap. An even smaller yield is expected with dry air or CO2

6) We recommend that a Finite-Element-Analysis (FEA) be undertaken for the entire detector,considering all loads generated in transport, installation, and maintenance. The analysis was done for the RICH structure, the mirrors and aerogel supports for different orientations of the RICH sector as reported in chapter 10 of TDR and in the “Mechanical Design” talk. Dedicated transport and installation procedures will be finalized in parallel with the mechanical design.


37Contalbrigo M.

Technical Review Recommendations7) We recommend that the collaboration focus R&D efforts to develop a reliable time line that leads to a mirror system which can be adequately characterized prior to installation. We adopt standard technologies commercially available. The construction plan is discussed in the “Project Management” document and talk. 8) We recommend that aging studies be initiated to check the long-term effects on the dark current of the H8500 when operated at 1075 V.

To run at 1075 V is not anymore required thanks to an improvement of the MAROC3 front-end card. Aging tests are anyway planned in September 2013. 9) We recommend that a procedure be developed to provide some characterization of the pixel by pixel response of each MAPMT, possibly through a gain measurement in response to uniform illumination. An automatized pico-second laser test bench is already in operation as shown in chapter 7 of TDR and in the “H8500 Tests” talk. An online pixel by pixel gain calibration is foreseen by analog readout of SPE dark counts, see chapter 8 of TDR and Front-End electronics talk.


38Contalbrigo M.

Technical Review Recommendations10) We recommend that the collaboration analyze and adopt a firm decision date, at which point they revert to H8500 MAPMTs, at least for this first RICH sector, if Hamamatsu cannot demonstrate mass production of H12700 units. The chosen deadline (1st February 2014) accounts for the H12700 estimated production time as discussed in the “Project Management” talk. 11) We recommend that the collaboration develop a full plan for the readout and DAQ with a cost analysis to identify responsibilities for design, construction and implementation.

The task sharing between INFN (Front-End) and JLab (DAQ) optimizes the complementary competences. Cost analysis and construction plan are discussed in the “Project Management” document and talk.

12) We recommend that Jlab/Hall-B provide a defined volume for the RICH detector, including available cooling and cabling spaces, as well as defining the required attachments to the forward carriage.

The RICH is design to fit into the LTCC clearance and weight with same joints to the forward carriage, as discussed in chapter 10 of TDR and “Mechanical Design” talk. The service (HV and LV cabling, readout optical fibers and gas lines) route and connectors along the torus coil shadow mimic the ones of LTCC.


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Technical Review Recommendations

13) We recommend that Jlab/Hall-B provide a suitable limiting temperature in the region of the FTOF and that the collaboration demonstrate by calculation that this limit can be held. Suitable steps should be taken to protect against a failure of the airflow.

The power consumption of the readout electronics (~400 W) is discussed in chapter 8 of TDR and in the “Front-End” talk. Standard temperature mitigating measures and slow-control monitors exist to keep the temperature below the 100 F (38 C) limit, as shown in chapter 10 of TDR and “Mechanical Design” talk. 14) We recommend that the collaboration develop a detailed work-breakdown that includes the resources required for each step in order to track closely the schedule. The Project Plan is ready and discussed in the “Management Plan” document and talk.


rich p roject o verwie v

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